An integrated development environment (“IDE”) is typically used to develop software in a “target” computer system. The IDE includes one or more “host” installations which may be connected to the target system in order to load the developed software into the target system and monitor its execution. A number of alternatives exist for connecting the target system to the host, but usually the connection is either an Ethernet or serial link.
In a development system, the host is typically equipped with large amounts of RAM and disk space, backup media, printers, and other peripherals. In contrast, the target system typically has limited resources (small amounts of RAM, no disk, no display, etc.), and perhaps some small amount of additional resources for testing and debugging. The target may include no more than a processor with on-chip RAM and a serial input/output channel. The target's processor may be of various kinds including the PowerPC® processor manufactured by IBM Corp. or the Pentium® II manufactured by Intel Corp. The target may also include an operating system, such as VxWorks® from Wind River Systems, Inc., which may be used to control the allocation and usage of the target's resources.
The IDE may include a number of “tools” that allow a software developer to easily develop software for the target system and monitor the generation of the developed software on the target system. One such tool may be an “object browser” which can be conveniently used to monitor the state of the target system while developed applications are executing. The object browser can be used to display information about “objects” in the system, for example, information about objects of the operating system executing on the target. These objects may include tasks, semaphores, message-queues, memory-partitions, watchdogs, etc. Each object also has attributes which are the properties of the object. For example, a semaphore (an object) may have as attributes its name, identification number, and state (e.g., whether the semaphore is taken). The attributes of an object may be static (i.e., determining the object attribute does not require access to the target system) or dynamic (i.e., determining the object attribute does require access to the target system). The static attributes of the object may include, among others, a string describing the type of object (e.g., for the semaphore, the string may be “Semaphore”). The dynamic attributes may include, among others, the name of the object, the object's identification number, and the state of the object.
In a host-target development environment, in order for the host to gather information about the objects running on the target, the host generally has one or more files describing the target system's implementation of the object and this description file is specific to the implementation of the object by the operating system running on the target system. For example, the description files can list offsets to internal fields within each object's data structure, allowing the tools on the host to locate information concerning the object running on the target system. Information concerning the object is then retrieved from the target system using a standard communication protocol such as a Gopher program. The Gopher program describes a sequence of memory reads which results in a sequence of data to be returned to the calling host.
This scheme just described for gathering information is unwieldy in practice and not easily scalable. It is expensive to extend and maintain because introducing a new object requires updating many architecture specific files.